For example, Japanese Laid-Open Patent Publication No. 2000-253457 discloses a telephone machine or a facsimile machine (hereinafter, referred to as a communication device) that can perform communications with an external terminal via voice or facsimile while connected with a public telephone line. In the communication device, various personal information including telephone numbers and/or facsimile numbers can be stored in a storage portion thereof, as telephone directory data, in addition to a dialed call history and a received call history.
However, for example, if such a communication device is stolen or is given to another person, there is a possibility that the stored personal information may be discovered, accidentally or intentionally, by another person, that is, the personal information may leak out to third parties.